Migrate WebRTC on FrameGeneratorInterface and remove FrameGenerator class

Bug: webrtc:10138
Change-Id: If85290581a72f81cf60181de7a7134cc9db7716e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161327
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30033}
diff --git a/call/bitrate_estimator_tests.cc b/call/bitrate_estimator_tests.cc
index b5c4d8e..50da12b 100644
--- a/call/bitrate_estimator_tests.cc
+++ b/call/bitrate_estimator_tests.cc
@@ -12,6 +12,7 @@
 #include <memory>
 #include <string>
 
+#include "api/test/create_frame_generator.h"
 #include "call/call.h"
 #include "call/fake_network_pipe.h"
 #include "call/simulated_network.h"
@@ -180,8 +181,8 @@
       frame_generator_capturer_ =
           std::make_unique<test::FrameGeneratorCapturer>(
               test->clock_,
-              test::FrameGenerator::CreateSquareGenerator(
-                  kDefaultWidth, kDefaultHeight, absl::nullopt, absl::nullopt),
+              test::CreateSquareFrameGenerator(kDefaultWidth, kDefaultHeight,
+                                               absl::nullopt, absl::nullopt),
               kDefaultFramerate, *test->task_queue_factory_);
       frame_generator_capturer_->Init();
       send_stream_->SetSource(frame_generator_capturer_.get(),